Hydraulic jack.



W. J. DRUGAN.

HYDRAULIG JACK.

APPLIGATION FILED FEB. 2, 1912.

Patented Dec( 10, 1912 2 SHEETS-SHEET 1,.

W. J. DRUGAN. HYDRAULIC JACK.

y APPLICATION FILED FEB. 2, 1912.

Patented Dec. 1o, 1912.

2 SHEETS-SHEET 2.

Vso

is less than the'said outer piston and in the WILLIAM J. DRUGAN, oF PORTSMOUTH, oHIo.

HYDRAULIC J' ACK.

Specification of Letters Patent.

Patented Dee.1o,1`912.

application mea-February a, i912. serial No. 674,931.

To all whom t may concern.'

Be it known that l, `W1LLIAM J DRUGA'N, a citizen of the United States, residing at Portsmouth, in the county of Scioto and State of Ohio, have invented new and useful lmprovements in Hydraulic Jacks, of which the following is a specification. l

The general object of the invention is to provide means .for expediting the raising or positioning of the lifting head of a lhydraulic jack intoy contact with the object to be lifted. And to this end the invention consists in providing a hydraulic jack with pump pistons of different liquid lifting capacities, the larger of which ao'rds a' means for rapidly lifting the head into contact with the object to be lifted, while the` smaller which serves to operate the head to lift the object, operates to move the said head more slowly.

Other objects will appear and be better understood from the following description talren in connection with Athe accompanying drawings, in which;

Figure. 1 is a side elevation ofthe device partly insection. Fig. 2 is a vertical longitudinall section looking at right angles to Fig. 1. -F ig. 3 is a detail section of the upper portion of the device showing'the posi- .tions of the parts with the` pistons locked. Fig. 4 is a sectional plan view of the head or reservoir with the pistons and the operating mechanism therefor removed. Fig. 5 is a detail plan of the barrel. Fig. 6 is a vertical longitudinal section of the same. Figs. 7 and '8 are detail perspectives of the device for locking the outer piston to the head.l

The barrel a is suitably connected to the base b and contains the lifting plunger 5 which is adapted to slide in the barrel vand which is suitably connected at one end to the hollow head' 6. l

The rock shaft '7 which is journaled in the` head 6 and has one end thereof adapted for connection to a suitable operating handle 8, is connected so as to operate a.double crank 9 which'operates the pistons 10 and 11.

v The liquid lifting capacity of the Ainner piston 11 which slides in the outer piston 10,

construction shown the outer piston 10 may be locked against movement whenever desired and the inner piston operated by the rock shaft 7 In the embodiment shown the 5Vinner piston 11 has a groove or keeper. 12 which takes one end of a latch 13 extendlng through'the outer piston 10. The latch 13 has an arm portion 14 pivoted between lugs 16 and which isadapted to move the latch 13 inwardly under the action of a spring 17.

The lock 19 for the outerpiston is freely received in a longitudinal groove 20 in that yportion of the outer piston which slides through the opening 21 in the bottom of the head 6 and a portion of the lock 19 extends into a recess 22 .in the side of the opening 21 and thereby yholds the said outer piston against turning movement. Shoulders 23 and 24 on the lock bear on the opposite faces of the body and thereby hold the lock against-1novernent with the piston. The upper end of the lock has lateral rarms 25-25 which when the outer piston is moved downV wardly as far as it will go, extend above an inturned portionv 26 at the ,free end of the arm portion 14 of the latch. This inturned portion 26 of the arm 14 has a recess 27 Y made to receive theportion of the lock protruding-beyond the groove 20 so that when the portion 14 `is moved inwardly by any suitable means such as fia set screw 28 inone side of the head 6, the?L inturned portionI 26 will move below the arms 25-,25 and,'since retract the latch 13 the inner piston 11 will be free to move, while the engagement loe-- The cylinder 29 is detachably connected `in any suitable manner such as by screw threads, with the lifting plunger 5. Suitable packing 30 at the lower end of this cylinder prevents the escape of liquid around the plunger 5. The cylinder is adapted to receivethe head -31 of the outer piston and the portion c of the cylinder located beyond the screw threads thereof, is contracted so as to provide a space for the liquid which 1sl introduced into the head through a capped` ment 38.

block by means ofk a cage 37 and controls the passage from the chamber into the cyl'- inder 29. The valve 36 closes under downward pressure thereon, whereby, the passage from the upper chamber to the space surrounding the cylinder is preventedduring the downward movementv of either piston. Communication between the cylinder and the lower compartment 38 of the block 35 is established by means of vvertical openings, ports, or passages 39 which open at`0ne end through theupper end of the block andl at their lower ends communicate with lateral ports or passages 40 which extend into the lower compartment 38. Thus, during the downward movement of either piston the water is forced through the openings or passages 39 and -40' and into the lower compart- AA check valve 41 controls communication between the lower compartment 38 and the barrel a below the lifting plunger 5. This check valve 41 is retained in the lower com-- part-ment by a cage 42 and yields or opens under downward pressure such as by the wa. ter moving through the passages 39 and 40, but closes under upward pressure and is .yieldingly held in its seatby `a spring 43.

Thus, it will be seen that when the pistons are latched and the operating handle 8 oscillated, arelatively large amount of water will be drawn from the passage surrounding the lifting plungeriand forced into the barlrel a. Thiswill have the effect ofmoving thex lifting plunger upwardly and more l In order to cause the 'lifting-plunger to descend, I"provide a release valve 44 in the form of a rod which extends through a pas l vsage 45 'in the wall of the cylinder 29, the

. lowerend of this passage Abeing sealed by a head 45 of the rod. The upper end of the rod extends through' the-bottom of the bead l 6` and the rod -is adapted to be pressed up- Wardly by a spring 4'6 so that the head of the rod will normally seal the lower end of the opening through which it extends.

The valve is 'caused to descend by means of an arm 47 on a shaft 48 arranged Iin the head 6 and the shaft is rocked by any suitable means such as a set screw 49 which ex tends through one side of the head and is adapted when screwed to move an arm 50 arranged in angular relation to the arm 47 and located on the shaft 48.

Although I have shown and described one embodiment of my invention it is to be understood that I am not to be limited to the specific arrangement and construction of parts since various changes may be made, within the scope of the appended claims without departing from the spirit or sacrificing any of the advantages of the invention.

What I claim as new is:

1. In a hydraulic jack, the combination with a barrel and a liquid operated lifting plunger arranged in the barrel; of ,a plurality of pistons arranged one within the other andadapted for lifting liquid and forcing it into the barrel, and means for locking one of said pistons to the lifting plunger for the purpose set forth.

2. In. a hydraulic jack, the combination with a barrel and a liquid operated lifting plungerarranged in' said barrel, of a head carried by said plunger, a plurality of pistons arranged one within the other and adapted for lifting liquid and forcing it into said barrel, and means in said head for locking said pistons together.

3. In a hydraulic jack, the combination with a barrel and a liquid operated lifting plunger arranged in the barrel; of a plurality of pistons adapted for lifting liquid and forcing it into the barrel, and means for locking one of said pistons to the lifting plunger.

4. In a hydraulic jack, the combination lwith a barrel and a lifting plunger having a hollow liquid holding head; of means for pumping liquid from the head into the barrel and including a plurality 'of pistons arranged. one within the other, and mea-ns in said head and supported by the outer piston for locking both of said pistons together.

In testimony whereof I aiix my signature two witnesses.

in presence of WILLIAM J. DRUGAN.

Witnesses:

FRANCIS DRUGAN,

FANNm. OCoNNoR. 

